This proposal outlines the development of an animal model of apnea in order to study the clinical problem of central alveolar hypoventilation in infants and young children. Individuals who fail to maintain an appropriate level of ventilation because of a reduced respiratory drive are at risk for congestive heart failure, brain damage and death. The primary aims of this project are: (1) To compare the problems of diaphragmatic pacing in infants to older children and adults. It appears as if infants may have special problems with respect to the uniformity of alveolar ventilation and ventilation perfusion matching, which may make the design of an electrical pacing system more of an engineering and surgical challenge; (2) To study the electrical support of ventilation in experimental animals whose innate system has been depressed or destroyed; (3) To design and evaluate an open loop system for providing long term respiratory support to those individuals requiring direct diaphragm pacing; (4) To develop strategies of closed-loop or demand respiratory pacing employing the patient's own muscle (EMG) or blood gas parameters; (5) As an outcome of this project, to eventually develop a completely implantable fail safe respiratory pacer with internal logic for control and provision for the external telemetering of respiratory patterns and physiological parameters.